I drilled out the center holes in the brace for the 1/4x28 lock plates. I then use the lock plate itself as a jig to drill the two rivet holes for each lock plate. Once all the holes were drilled and de-burred, I riveted the lock plates in the reverse of how they are normally installed using stainless rivets. I stick the neck of the lock plate through the hole from the inside of the brace to give the lock plate the lowest profile possible toward the seat back. This allows more adjustment of the angle of the seat back.
Once installed, I inserted a
1/4x28 stainless bolt to test it out. Adjusting the seat back is done on the
ground and must be done equally on both sides of the seat so as not to
distort the seat back frame and cause unnecessary stress on the assembly. After
looking at the setup, I think a jam nut would be a good idea to lock the
position into place. This mod is not intended to be adjusted in flight. It is
merely an adjustment that is usually setup once and locked in.
